1. Field of the Invention
This invention relates to an organic EL (electroluminescent) device comprising, on a substrate, a structure in which organic luminescent material is disposed between a pair of electrodes which face to each other, and having a protective layer for covering the organic luminescent material on the outer surface of the structure.
2. Description of the Related Art
In general, an organic EL device comprises, on a substrate, a structure in which organic luminescent material is disposed between a pair of electrodes that face to each other. However, it has had a problem that the organic luminescent material deteriorates due to moisture within the use environment, thus causing a non-luminescent area in the luminescent area of the structure and aggravating the quality of display. In order to solve this problem, Japanese Patent Laid-Open No. Hei. 7-161474 proposes a method of forming an inorganic amorphous film made of carbon or silicon by CVD (chemical vapor deposition) so as to cover the organic luminescent material on the outer surface of the structure and of using it as a protective layer.
However, according to the study conducted about the above-mentioned publication, it has been found that the moisture resistance of the protective layer is low because its coverage over the structure is insufficient and that it causes a non-luminescent area when it is operated in a high-temperature and high-moisture atmosphere (65° C. and 95% RH for example).